Coronary artery bypass grafting (CABG) has traditionally been performed with the use of a cardiopulmonary bypass (CPB) machine to oxygenate and perfuse the body during surgery. Recently, techniques have been developed to allow for performing CABG without the use of CPB by stabilizing the epicardial surface of the beating heart at the coronary anastomosis site with a stabilizer of some sort to allow placement of sutures through the graft vessel and recipient coronary artery. This procedure may be performed through a stemotomy, mini-stemotomy, thoracotomy or mini-thoracotomy, or less invasively through a port provided within the chest cavity of the patient, e.g., between the ribs or in a subxyphoid area, with or without the visual assistance of a thoracoscope.
Oftentimes, one or more arteries of interest are located on the lateral or posterior aspects of the heart, making access to such arteries difficult, especially in a minimally invasive procedure such as port access and the like. For other arteries, access is typically not so problematic, for example if the left anterior descending (LAD) artery is the artery of interest, access is easily accomplished using either a stemotomy or a thoracotomy approach. However, oftentimes other arteries may be involved in the bypass procedure. For example, the patient may require bypass to multiple coronary arteries, including the circumflex artery (CxA) on the left lateral aspect of the heart, the right coronary artery (RCA) on the right lateral aspect of the heart, and the posterior descending artery (PDA) on the back side of the heart. It is very difficult to access the CxA, RCA, and PDA without a stemotomy, as the heart needs to be turned and/or tilted significantly to give a surgeon access to its side or back and, with an intact sternum, insufficient space exists for these maneuvers of the heart. When a stemotomy is performed, the apex of the heart is generally lifted out of the body through the stemotomy in order to reach the PDA. Contrarily, in minimally invasive procedures such as closed chest procedures and the like, arteries located on the lateral and/or posterior aspects of the heart are extremely difficult to access because the heart can not be so easily manipulated.
An additional challenge to heart manipulation during beating heart surgery is that some hearts do not hemodynamically tolerate manipulation well. Thus, even if the heart could be sufficiently manipulated to enable access to lateral and posterior arteries, it must be done with minimal or no adverse hemodynamic consequences. Conventional techniques and devices employed to manipulate the heart typically suffer from one or more disadvantages including cardiac contraction and expansion constraint, limited use, e.g., useful only for arrested hearts and limited range of motion.
For example, a common technique used with a sternotomy approach involves the use of pericardial sutures to retract the heart into the proper position for surgery. However, conventional use of pericardial sutures for retraction of a beating heart is inconvenient and potentially harmful to the patient. In such a procedure, the pericardium is incised and sutures are inserted along cut edges of the pericardium, and then tension is exerted on the sutures to move the heart together as a unit with the pericardium. When the sutures are pulled to lift the heart (with the pericardium), compressive force exerted by the pericardium on at least one side of the heart sometimes constrains cardiac contraction and expansion.
U.S. Pat. No. 5,799,661 to Boyd, et al., describes (with reference to FIGS. 33A–33C) a suction cup-shaped manipulator on a long shaft. The suction cup is to be attached to an arrested heart by suction, and the device is then used to move the heart within the chest cavity. A vacuum is applied to the cup to provide suction, and the vacuum is said preferably to have a value not less than −150 mmHg (to avoid tissue damage). The suction cup is made of a soft, flexible elastomeric material such as silicone rubber, has a diameter of approximately 12 mm to 50 mm, and has a textured, high friction distal surface (for gripping the heart). The high friction can be achieved by a pattern of bumps or an absorbent high friction material (such as non-woven polyester fabric).
The suction cup of U.S. Pat. No. 5,799,661 is apparently flexible relative to the distal end of a rigid shaft. However, U.S. Pat. No. 5,799,661 does not teach attaching the suction cup to the shaft by a joint or other mechanical element to provide limited freedom to translate along a first axis and/or freedom to rotate about the first axis. Without such provisions to allow a beating heart to translate and/or rotate in a manner which does not negatively effect hemodynamics, the suction cup apparatus described in U.S. Pat. No. 5,799,611 is useful only to retract an arrested heart.
Accordingly, there is continued interest in the development of new devices and methods for use for easily and effectively manipulating and supporting an organ such as a beating heart without compromising the hemodynamic stability thereof. In other words, there is a need for organ manipulation and support devices and methods of use capable of physically translating a beating heart from its natural resting place to a location better suited to surgical access, and then holding the beating heart in the latter location during surgery without compressing (or otherwise deforming) the heart or great vessels in such a way that hemodynamic function is compromised. Of particular interest would be the development of such devices and methods of use which may be used in a variety of surgical approaches, including a full and partial sternotomy, a full and partial thoracotomy and port access or endoscopic or thoracoscopic procedures and used with a variety of organs.